Preliminary X-ray fluorescence imaging experiments were performed on the BioCAT ID line on frog eggs. A 50 micron pin-hole was used. With a focusing spot (FWHM) of 0.3 mm horizontal and 0.15 vertical, the photon flux into the pin-hole was 2X1011. A multilayer analyzer detector developed by BioCAT was used for the data collection, which can be tuned to select certain energy photons and discriminate against the others. Frog eggs were mounted in a plastic sample holder. The profile of the egg can be determined by transport it in the beam by monitoring transmission and/or scattering. In this manner, zinc concentration profile were obtained by monitoring the x-ray fluorescence signal over a time period after fertilization. It was found that zinc signal are unevenly distributed in the oocytes starting from a more or less even distribution at the zero time. It is evident that zinc distributes towards one side within the oocytes after fertilization. Further studies are underway to reveal zinc transport during oocytes development.